update version to try and fix workflow

Author: zjaco13

.github/workflows/markdown-link-check.yaml

@@ -20,7 +20,7 @@ jobs:
       - uses: actions/checkout@v3
       - uses: actions/setup-node@v3
         with:
-          node-version: '18.x'
+          node-version: '20.x'
       - name: install markdown-link-check
         run: npm install -g [email protected]
       - name: markdown-link-check version